Jump to content
Sign in to follow this  
michrist

Focusing in dark water

Recommended Posts

How do you guys get your cameras to focus in dark water? Are there any settings that could be useful? Is the only answer focusing lights? Is manual focus a practical solution?

 

This is really troubling me, as I do most of my diving in Denmark and Norway. My setup is an Oly E410 in a PTE-03 housing, 1 Inon D2000 and I am using the standard 14-42 + a 50mm macro. None of them seems able to focus on anything more than a few feet away below 20 meters. Are Nikons and Canons better at focussing or how does folks like Leigh Bishop manage to get those photos of deep wrecks?

Share this post


Link to post
Share on other sites

In my humble opinion, focus lights are absolutely the way to go. If it is dark enough that autofocus is having a hard time, it is likely that your eyes will have a hard time too. Focus lights can start out cheap (dual Q40 mask lights) and work their way into the cost stratosphere. Personally I think that some of the high end focus lights go a bit overboard. You want them to help the camera focus, not necessarily to provide enough light to photograph by. That role is better left to your strobes. That being said I have a Nocturnal Lights SLX focus lamp which I use as a primary dive light during night dives with my camera. It isn't as bright as my Light Canon, but I don't know how I would mount my Light Canon on the camera!

Edited by drsteve

Share this post


Link to post
Share on other sites

Hi Steve and thanks. I guess I'll just have to get some stronger focuslights then. I was hoping there was a clever trick, because my eyes are certainly able to focus in much less light than the camera.

Share this post


Link to post
Share on other sites

The way I do it and the way I believe Leigh Bishop has done at one point in time at least is to use fixed focus. The optics of a dome port (a subject treated in many threads here) mean that you can actually get pictures that are sharp from a few tens of cm to infinity with a single focus setting. The way I set my system up (using Nikon 10.5mm and Hugy 180mm dome) is that I set the lens on 35cm and will get a sharp focus on anything between, say, 50cm to infinity.

 

The best setting for the focus can be either calculated or tested in a pool. I have used the latter approach.

 

This method, of course, is really only practical if using prime lenses I think. Have not actually ever used a zoom underwater...

 

Otoh, focus lights are sort of difficult to use if shooting natural light (as myself and Mr. Bishop are fond of doing). Unless, that is, you go with one of the high-end trigger activated models.

 

timo

Share this post


Link to post
Share on other sites

Hi Timo. That's interesting, but why would it not be practical with a zoom lens? I'll see if I can make that work.

Share this post


Link to post
Share on other sites
Hi Timo. That's interesting, but why would it not be practical with a zoom lens? I'll see if I can make that work.

 

It can still work. Just make sure you keep it zoomed all the way out. The more you zoom the shorter your depth of field.

Share this post


Link to post
Share on other sites
Hi Timo. That's interesting, but why would it not be practical with a zoom lens? I'll see if I can make that work.

 

Please do.

 

To be honest, I have never tried as I do not own any suitable zoom lenses, not to mention the needed port/extension combos. My impression is that with (most) zoom lenses the focus setting changes slightly when zoom setting changes. This may or may not be material behind a dome. Dunno really.

 

timo

Share this post


Link to post
Share on other sites

Hi again. I tried experimenting a little. Conditions were really poor, viz < 2 metres. I used the 14-42mm standard zoom behind an Athena port, f11 at 1/80 (and a flash) - and it seems to work wonderfully allthough it needs a little more testing. After the dive I couldn't remember which ones were 'autofocus' and which ones weren't ;) and I couldn't tell (that must be good).

Share this post


Link to post
Share on other sites

For strobe lit w/a shots in dark water I use two 1 watt lamps (aquatec aquastars) mounted under the tray. Their beams are sufficiently diffused so as not to cause hotspots in the centre of the image.

Share this post


Link to post
Share on other sites

Canon and Nikon dslrs have better focusing abilities than your olympus compact will. Not to mention zero shutter lag. I have a 5d with a ds200 and I do have some problems at night getting the aiming light right where I need it. Other than that It is very good at focusing better than I could do manually.

 

good luck

Share this post


Link to post
Share on other sites

The Oly E410 is not a compact, and doesn't really suffer from extreme shutter lag. That said, the Canon and Nikons might still focus a bit faster, and have more focus zones (the 410 only has 3). But otherwise, this is not a point-n-shoot issue.

 

I shoot an E330, which has essentially the same focus features as the 410, and did notice on dimmer dives (early morning, shadowed side of reef) I had a bit more trouble focusing without my focus light. I use just a small Fisheye Nano. I also set the AF to only use the 'middle' zone, and just use S-AF mode vs. continuous AF...if I want to intentionally focus on something I want off-center I use the half-shutter-press to lock focus and then reframe before a full shutter press to actually capture the shot.

 

I am however also using the upgrade 14-54 lens, which is a bit brighter (wider aperture possible) and faster at AF than the 14-42. That might make a difference for you as well. Watch ebay and you can find them for $300-325 now, since the 12-60 is getting all the glamour press being all newer and having the SWD speedier stuff....

Share this post


Link to post
Share on other sites

I mistakingly used my 18-35 zoom lens on my D80 and also had a hard time focusing (low vis) is there a problem w/ using the model light on my YS110's? Is it also becuase i was not on a fixed focal length that made the camera confused ( as well as its operator? :uwphotog: )

Share this post


Link to post
Share on other sites
Sign in to follow this  

Sponsors

Advertisements



×
×
  • Create New...